1. maid/dog, maid rt (return)
2. maid/daugter1, maid and dog rt
3. mother and daughter 2; mother rt
4. father and mother; father rt
5. maid and dog; mother rt
6. mother and father; father rt
7. father and son 1; mother and father rt
8. father ans son 2; father rt
9. father and mother final crossing.

I'm afraid both solutions fail at step 8. Let's look at the first solution. When, at step 8, father and son 2 cross the river, on the other side there will be 2 daugters without mother.

Correct solution is:

maid and dog, maid rt
maid and son 1, maid and dog rt
father and son 2, father rt
father and mother, mother rt
maid and dog, father rt
father and mother, mother rt
mother and daughter 1, maid and dog return
maid and daughter 2, maid rt
maid and dog final crossing

When we interchange sons with daughters and father with mother, we'll get another solution